Abstract:

CCSDSK2 East Borehole is the main borehole of China Continental Scientific Drilling Project in Songliao Basin, which is designed to reach a depth of 6400 m to penetrate Cretaceous strata. Its implementation is important for the research of the Cretaceous sedimentary environment and climate, for the achievement of new breakthroughs in oil and gas exploration, for the enhancement of the deepdrilling level and geophysical logging techniques, etc. Based on the scientific objectives and tasks of this project, combined with the design of drilling engineering and the characteristics of well conditions, the authors carried out the logging design of CCSDSK2 EastBorehole，intending to adopt the most advanced equipment to acquire log data. The adopted logging suits include comprehensive logging in openhole and cementevaluation logging in cased hole. Based on the situation of drilling times and programs, eight times of comprehensive logging and five times of cementevaluation logging are designed respectively, and comprehensive logging suits in different drilling times are different; taking into account the challenge of high temperature under the depth of 4500 m, logging items are designed including both required and selected ones. This logging design not only seeks to completely acquire all kinds of log data, but also conduces to flexibly deal with complex conditions of the borehole, which would be beneficial to the achievement of scientific goals.

Key words: Songliao Basin, Cretaceous, Continental Scientific Drilling Project, CCSDSK2 East Borehole, geophysical logging design